JP2023098829A - Display device and method for manufacturing the same - Google Patents

Abstract

To provide a display device for causing a cathode electrode and an auxiliary electrode to come into direct contact with each other by a patterned auxiliary electrode structure, and a method for manufacturing the same.SOLUTION: A display device may include: a substrate including a light emitting region and an auxiliary electrode contact unit; an auxiliary electrode disposed on the auxiliary electrode contact unit and having an electrode hole formed therein; a transparent conductive layer covering the auxiliary electrode and having a groove unit formed on an upper section of the electrode hole; a bank exposing a periphery of the groove unit of the transparent conductive layer and covering a remaining region; an organic layer formed on the bank and the exposed transparent conductive layer; and a cathode electrode formed on the organic layer.SELECTED DRAWING: Figure 3

Description

The present invention relates to a display device and its manufacturing method.

Technology behind the invention

2. Description of the Related Art As the information society develops, various types of display devices are being developed. Recently, various display devices such as a liquid crystal display (LCD), a plasma display panel (PDP), and an organic light emitting display (OLED) have been used.

Since the organic light emitting diodes constituting the organic light emitting display are self-emitting and do not require a separate light source, the thickness and weight of the display can be reduced. In addition, the organic light emitting diode display has high quality characteristics such as low power consumption, high brightness, and high reaction speed.

Content of the invention

SUMMARY OF THE INVENTION Embodiments provide a display device and a manufacturing method thereof in which a cathode electrode and an auxiliary electrode are in direct contact with each other through a patterned auxiliary electrode structure.

A display device according to an embodiment includes a substrate including a light-emitting region and an auxiliary electrode contact portion, an auxiliary electrode disposed on the auxiliary electrode contact portion and having an electrode hole formed therein, covering the auxiliary electrode, a transparent conductive layer having a groove formed above the electrode hole; a bank exposing the periphery of the groove of the transparent conductive layer and covering the remaining area; formed on the bank and the exposed transparent conductive layer; An organic layer and a cathode electrode formed on the organic layer may be included.

The cathode electrode may be in direct contact with the inner surface of the groove.

The organic layer may be interrupted around the groove to expose an inner side surface of the groove, and the cathode electrode may be in direct contact with the exposed inner side surface of the groove.

The transparent conductive layer may cover the auxiliary electrode as a whole and have a larger area than the auxiliary electrode.

The auxiliary electrode has a structure in which a first transparent conductive layer, a reflective layer, and a second transparent conductive layer are laminated, and the reflective layer is exposed on the inner surface of the electrode hole and covered with the transparent conductive layer. may

The reflective layer may be recessed further from the inner surface of the electrode hole than the first and second conductive layers.

The reflective layer may have a reverse tapered side surface, and the groove of the transparent conductive layer may have a reverse tapered shape corresponding to the shape of the reflective layer.

The reflective layer may have a tapered side surface, and the groove of the transparent conductive layer may have a tapered shape corresponding to the shape of the reflective layer.

The auxiliary electrode may have a structure in which a first transparent conductive layer and a reflective layer are stacked, and the exposed reflective layer may be entirely covered by the transparent conductive layer.

The auxiliary electrode may have a structure in which a first transparent conductive layer and a reflective layer are laminated, and the first transparent conductive layer may be entirely covered by the transparent conductive layer.

The auxiliary electrode may have a structure in which a first transparent conductive layer is laminated, and the first transparent conductive layer may be entirely covered by the transparent conductive layer.

The first bank may be a hydrophilic bank and the second bank may be a hydrophobic bank.

A method of manufacturing a display device according to one embodiment includes the steps of: forming an auxiliary electrode on the auxiliary electrode contact portion of a substrate including a light emitting region and an auxiliary electrode contact portion; forming a transparent conductive layer covering the auxiliary electrode; exposing at least one region of the transparent conductive layer and forming a bank covering the remaining region; forming an organic layer on the bank and the exposed transparent conductive layer; and forming a cathode on the organic layer. Forming an electrode may also be included.

The transparent conductive layer may be formed to cover the auxiliary electrode as a whole and have a larger area than the auxiliary electrode.

The step of forming the auxiliary electrode includes stacking a first transparent conductive layer, a reflective layer and a second transparent conductive layer, and performing an etching process with a mask applied to form an electrode hole, The reflective layer may be exposed on inner surfaces of the electrode holes and covered by the transparent conductive layer.

The reflective layer may be overetched from the first and second transparent conductive layers during the etching step.

Forming the bank may include forming an insulating layer, performing an etching process with a mask applied to form the bank, and performing an ashing process to remove the mask.

The organic layer and the cathode electrode may be formed to have a large area on the substrate by evaporative deposition or physical vapor deposition.

Effect of the Invention In the display device and the manufacturing method thereof according to the embodiment, the sides of the electrode holes patterned in the auxiliary electrodes are covered with the transparent conductive layer, so that the banks are ashed for the contact of the auxiliary electrodes. To prevent particles from being generated at the side of the electrode hole when the electrode hole is formed. Accordingly, the display device and the manufacturing method thereof according to the embodiment can solve the problem that particles are visually recognized as dark spots in the auxiliary electrode contact portion.

In addition, the display device and the manufacturing method thereof according to the embodiment can improve the contact efficiency of the auxiliary electrode by increasing the length of the tip of the auxiliary electrode.

The display device and the manufacturing method thereof according to the embodiment can facilitate contact between the cathode electrode and the auxiliary electrode and reduce the resistance between the cathode electrode and the auxiliary electrode.

1 is a block diagram showing the configuration of a display device according to an example; FIG. 2 is a circuit diagram showing one embodiment of a pixel shown in FIG. 1; FIG. 1 is a cross-sectional view of a display panel according to one embodiment; FIG. FIG. 4 is a cross-sectional view showing an auxiliary electrode contact portion according to the first embodiment; FIG. 5 is a cross-sectional view showing an auxiliary electrode contact portion according to a second embodiment; FIG. 11 is a cross-sectional view showing an auxiliary electrode contact portion according to a third embodiment; FIG. 11 is a cross-sectional view showing an auxiliary electrode contact portion according to a fourth embodiment; FIG. 11 is a cross-sectional view showing an auxiliary electrode contact portion according to a fifth embodiment; FIG. 11 is a cross-sectional view showing an auxiliary electrode contact portion according to a sixth embodiment; FIG. 10 is a diagram illustrating a method of manufacturing a display device according to one embodiment; FIG. 10 is a diagram illustrating a method of manufacturing a display device according to one embodiment; FIG. 10 is a diagram illustrating a method of manufacturing a display device according to one embodiment; FIG. 10 is a diagram illustrating a method of manufacturing a display device according to one embodiment; FIG. 10 is a diagram illustrating a method of manufacturing a display device according to one embodiment; FIG. 10 is a diagram illustrating a method of manufacturing a display device according to one embodiment; FIG. 10 is a diagram illustrating a method of manufacturing a display device according to one embodiment;

Specific content for carrying out the invention

Various embodiments will be described below with reference to the drawings. In this specification, when a component (or region, layer, portion, etc.) is referred to as being “on,” “connected to,” “contacted with,” or “coupled to” another component , which means that it can be directly linked/bonded onto another component or a third component may be placed between them.

The same reference numerals refer to the same components. Also, in the drawings, the thicknesses, proportions, and dimensions of components are exaggerated for effective description of technical content. "And/or" includes all combinations of one or more for which a related construct can be defined.

The terms first, second, etc. may be used to describe various components, but the components are not limited by the terms. The terms are only used to distinguish one component from another. For example, a first component could be termed a second component, and similarly a second component could be termed a first component, without departing from the scope of rights of various embodiments. Singular expressions include plural expressions unless the context clearly dictates otherwise.

Terms such as "below", "below", "above", "above" are used to describe the relationship of the illustrated configurations. The above terms are relative concepts and will be explained based on the directions shown in the drawings.

Terms such as "including" or "having" are intended to indicate the presence of any feature, number, step, act, component, part or combination thereof described in the specification; It is to be understood that it does not preclude the presence or addition of one or more other features, figures, steps, acts, components, parts or combinations thereof.

FIG. 1 is a block diagram showing the configuration of a display device according to one embodiment.

Referring to FIG. 1, a display device (1) includes a timing controller (10), a gate driver (20), a data driver (30), a power supply (40) and a display panel (50).

The timing controller (10) can receive video signals (RGB) and control signals (CS) from the outside. The video signal (RGB) may include multiple gradation data. Control signals (CS) may include, for example, horizontal synchronization signals, vertical synchronization signals and main clock signals.

A timing control unit (10) processes video signals (RGB) and control signals (CS) so as to meet operating conditions of a display panel (50), and outputs video data (DATA) and gate drive control signals (CONT1). , a data drive control signal (CONT2), and a power supply control signal (CONT3).

The gate drive section (20) can generate a gate signal based on the gate drive control signal (CONT1) output from the timing control section (10). The gate driver 20 may provide the generated gate signals to the pixels PX through a plurality of first gate lines GL11˜GL1n. The gate driver 20 may provide sensing signals to the pixels PX through a plurality of second gate lines GL21 to GL2n. A sensing signal may be provided to measure the characteristics of the driving transistor and/or the light emitting element provided inside the pixel (PX).

The data driver (30) can generate a data signal based on the video data (DATA) and the data drive control signal (CONT2) output from the timing controller (10). The data driver 30 may provide the generated data signals to the pixels PX through a plurality of data lines DL1-DLm. The data driver 30 provides a reference voltage (or sensing voltage or initialization voltage) to the pixels PX through a plurality of sensing lines SL1 to SLm or is fed back from the pixels PX. The state of the pixel (PX) can be sensed based on the electrical signal.

The power supply unit (40) can generate a high potential driving voltage (ELVDD) and a low potential driving voltage (ELVSS) to be provided to the display panel (50) based on the power supply control signal (CONT3). The power supply unit (40) can provide the generated drive voltages (ELVDD, ELVSS) to the pixels (PX) through corresponding power supply lines (PL1, PL2).

A plurality of pixels (PX) (also called sub-pixels) are arranged on the display panel (50). The pixels (PX) may be arranged in a matrix on the display panel (50), for example. The pixels PX can emit light with luminance corresponding to gate signals and data signals supplied through the first gate lines GL11 to GL1n and data lines DL1 to DLm.

In one embodiment, each pixel (PX) may display one of red, green and blue. In other embodiments, each pixel (PX) may display one of cyan, magenta and yellow. In various embodiments, each pixel (PX) may display one of red, green, blue, and white.

The timing controller (10), the gate driver (20), the data driver (30), and the power supply (40) are each composed of separate integrated circuits (ICs), or at least partially may comprise an integrated circuit integrated with the In addition, at least one of the gate driver 20 and the data driver 30 may be configured as an in-panel type integrally formed with the display panel 50 .

FIG. 2 is a circuit diagram showing one embodiment of the pixel shown in FIG. FIG. 2 shows an example of pixels (PXij) connected to the i-th first gate line (GL1i) and the j-th data line (DLj).

Referring to FIG. 2, a pixel (PX) includes a switching transistor (ST), a driving transistor (DT), a sensing transistor (SST), a storage capacitor (Cst) and a light emitting device (LD).

A first electrode of the switching transistor (ST) is electrically connected to the jth data line (DLj), and a second electrode is electrically connected to the first node (N1). A gate electrode of the switching transistor (ST) is electrically connected to the i-th first gate line (GL1i). The switching transistor (ST) is turned on when a gate signal of a gate-on level is applied to the i-th first gate line (GL1i), and the data signal applied to the j-th data line (DLj) is applied to the first node. (N1).

A first electrode of the storage capacitor (Cst) is electrically connected to the first node (N1), and a second electrode of the storage capacitor (Cst) is connected to a first electrode (eg, an anode electrode) of the light emitting device (LD). The storage capacitor (Cst) can be charged with a voltage corresponding to the difference between the voltage applied to the first node (N1) and the voltage applied to the first electrode of the light emitting device (LD).

A first electrode of the driving transistor (DT) is configured to receive a high potential driving voltage (ELVDD), and a second electrode is electrically connected to a first electrode of the light emitting device (LD). A gate electrode of the driving transistor (DT) is electrically connected to the first node (N1). The driving transistor (DT) is turned on when a gate-on level voltage is applied through the first node (N1), and the driving current flowing through the light emitting device (LD) corresponding to the voltage applied to the gate electrode is increased. You can control the amount.

A first electrode of the sensing transistor (SST) is electrically connected to the j-th sensing line (SLj), and a second electrode is electrically connected to the first electrode of the light emitting device (LD). A gate electrode of the sensing transistor (SST) is electrically connected to the i-th second gate line (GL2i). The sensing transistor (SST) is turned on when a gate-on level sensing signal is applied to the i-th second gate line (GL2i), and the reference voltage applied to the j-th sensing line (SLj) is applied to the light emitting element ( LD) to the first electrode.

A light emitting device (LD) outputs light corresponding to the drive current. A light emitting device (LD) can output light corresponding to any one of red, green, blue, and white. The light emitting device (LD) may be an organic light emitting diode (OLED) or a micro inorganic light emitting diode having a size in the micro to nanoscale range, but the present embodiment is not limited thereto. not Hereinafter, the technical concept of this embodiment will be described with reference to an embodiment in which the light emitting device (LD) is composed of an organic light emitting diode.

In this embodiment, the pixel (PXij) structure is not limited to that shown in FIG. Depending on the embodiment, the pixel (PXij) compensates the threshold voltage of the driving transistor (DT) or initializes the voltage of the gate electrode of the driving transistor (DT) and/or the voltage of the first electrode of the light emitting device (LD). It may further comprise at least one element for softening.

FIG. 2 shows an example in which the switching transistor (ST), driving transistor (DT) and sensing transistor (SST) are NMOS transistors, but the present invention is not limited thereto. For example, at least some or all of the transistors forming each pixel (PX) may be formed of PMOS transistors. In various embodiments, each of the switching transistor (ST), driving transistor (DT), and sensing transistor (SST) is a low temperature poly silicon (LTPS) thin film transistor, an oxide thin film transistor, or a low temperature polyoxide ( Low Temperature Polycrystalline Oxide (LTPO) thin film transistors.

FIG. 3 is a cross-sectional view of a display panel according to one embodiment.

Referring to FIG. 3, a pixel (PX) according to one embodiment includes a substrate (100), a circuit element layer formed on the substrate (100) and provided with at least one circuit element, and a light emitting element (LD). may include a light-emitting element layer.

The substrate (100) is the base material of the display panel (50) and may be a translucent substrate. The substrate 100 may be a rigid substrate including glass or tempered glass or a flexible substrate made of plastic.

The circuit element layer is formed on the substrate (100) and may include circuit elements (eg, transistors, capacitors, etc.) and wirings forming pixels (PX).

A first conductive layer may be disposed on the substrate (100). The first conductive layer may include auxiliary wiring (110). The auxiliary line 110 may be connected to a second power line (PL2) applied with a low potential driving voltage (ELVSS).

A buffer layer (120) is disposed on the substrate (100) to cover the first conductive layer. The buffer layer (120) can prevent the diffusion of ions and impurities from the substrate (100) and block the permeation of moisture.

An insulating layer (130) may be formed on the buffer layer (120). A second conductive layer may be disposed on the insulating layer (130). The second conductive layer may include a connecting electrode (140). The connection electrode 140 contacts the auxiliary wire 110 through a contact hole penetrating the insulating layer 130 and the buffer layer 120 .

The circuit element layer may be covered by a passivation layer (150) and an overcoat layer (160). The passivation layer 150 may be an insulating layer for protecting underlying devices, and the overcoat layer 160 may be a planarizing layer for reducing steps in the underlying structure.

A light emitting device layer is formed on the overcoat layer (160) and includes a light emitting device (LD). A light emitting device (LD) includes an anode electrode (210), a light emitting layer (220) and a cathode electrode (240).

An anode electrode (210) is formed on the overcoat layer (160). The anode electrode 210 may be made of a transparent conductive material such as ITO (Indium Tin Oxide), IZO (Indium Zinc Oxide), or ZnO (Zinc Oxide). When the anode electrode (210) is a reflective electrode, the anode electrode (210) may be formed of a triple layer consisting of a transparent conductive layer/reflective layer (metal oxide layer)/transparent conductive layer. For example, the anode electrode (210) may consist of a triple layer including ITO/Ag/ITO.

A bank (250) may be formed on the overcoat layer (160). The bank (250) may be formed to expose a partial area of the anode electrode (210), such as the central area, and cover the rest of the area, such as the edge. The exposed area of the anode electrode (210) not covered by the bank (250) can be defined as the light emitting area (EA) of the pixel (PX).

In one embodiment, the bank (250) may have a structure in which a hydrophilic bank (251) and a hydrophobic bank (252) are stacked. A hydrophilic bank (251) can expose the central region of the anode electrode (210) and cover the edges. The exposed area of the anode electrode (210) not covered by the hydrophilic bank (251) can be defined as the light emitting area (EA). The hydrophilic bank 251 is made of a hydrophilic inorganic insulating material such as silicon oxide (SiO2) or silicon nitride (SiNx) to allow the solution to spread well during the formation of the light emitting layer 220, which will be described later.

A hydrophobic bank (252) may be formed in a partial area on the hydrophilic bank (251). Hydrophobic banks (252) may be disposed between and partition the pixel rows. The hydrophobic bank (252) is configured such that at least one region, eg, the top region, is hydrophobic to prevent color mixing between pixel rows.

A light emitting layer (220) is formed on the exposed area of the anode electrode (210) surrounded by the bank (250). In one embodiment, the emissive layer (220) may be formed by a solution process. For example, a solution may be applied to form an emissive layer (220) within the emissive area (EA). The solution can be prepared by mixing an organic material for the emission layer 220 with a solvent. The solution may be jetted onto the light-emitting region by an inkjet device, such as an inkjet device with nozzles attached to an inkjet head. The applied ink dries to form a luminescent layer (220). The light-emitting layer 220 formed by a solution process may be formed such that the surface of the central region is lower than the surface of the edge region.

In one embodiment, a hole injection layer (211, Hole Injection Layer; HIL) and a hole transport layer (212, Hole Transport Layer; HTL) are provided between the light emitting layer (220) and the anode electrode (210). may be further arranged. The hole-injecting layer (211) and the hole-transporting layer (212) can be formed by a solution process, similar to the light-emitting layer (220).

An organic layer (230) may be formed on the emissive layer (220). The organic layer (230) may be widely formed on the substrate (100) to cover the light emitting layer (220) and the bank (250). The organic layer (230) may be formed by evaporation deposition methods, such as thermal evaporation, or physical vapor deposition methods, such as sputtering. The organic layer (230) may be, for example, an electron transport layer (ETL). The electron transport layer serves to smoothly transfer electrons injected from the cathode electrode 240 to the light emitting layer 220 .

A cathode electrode (240) is formed on the organic layer (230). A cathode electrode (240) may be widely formed on the substrate (100). The cathode electrode 240 may be made of a transparent conductive material (TCO) or a semi-transmissive conductive material that can transmit light. The cathode electrode (240) may be formed by evaporative deposition or physical vapor deposition, similar to the organic layer (230). For example, the cathode electrode (240) may be formed by codepositioning silver (Ag) and magnesium (Mg) and depositing them on the organic layer (230).

In this embodiment, the display panel (50) may include an auxiliary electrode contact portion (CA) for connecting the cathode electrode (240) to the low potential driving voltage (ELVSS). Hereinafter, the detailed configuration of the auxiliary electrode contact portion (CA) will be described with reference to FIG. 4 as well.

FIG. 4 is a cross-sectional view showing the auxiliary electrode contact portion (CA1) according to the first embodiment.

Referring to both FIGS. 3 and 4, the light emitting device layer further includes an auxiliary electrode (260) for connecting the cathode electrode (240) and the connection electrode (140). The auxiliary electrode (260) may be formed in the same layer as the anode electrode (210) and placed in the auxiliary electrode contact portion (CA1). The auxiliary electrode (260) contacts the connecting electrode (140) through a contact hole penetrating the overcoat layer (160) and the passivation layer (150). Since the connection electrode 140 is connected to the second power line PL2 through the auxiliary wiring 110, the auxiliary electrode 260 can be connected to the second power line PL2.

The auxiliary electrode (260) may be made of the same material as the anode electrode (210) and formed by the same process. In one embodiment, the auxiliary electrode (260) is formed of a triple layer consisting of a first transparent conductive layer (261)/reflective layer (262, metal oxide layer)/second transparent conductive layer (263). good too. For example, the auxiliary electrode (260) may consist of a triple layer comprising ITO/Ag/ITO.

An electrode hole (H) may be formed in the auxiliary electrode (260). At least one electrode hole (H) may be patterned on the auxiliary electrode (260). Such an auxiliary electrode (260) is formed, for example, by laminating a first transparent conductive layer (261)/reflecting layer (262)/second transparent conductive layer (263) in order, and then forming a pattern corresponding to the electrode hole (H). may be formed by collectively etching (eg, wet etching) the trilayer while applying a mask containing At this time, a region of the overcoat layer 160 stacked under the auxiliary electrode 260 may be exposed upward through the electrode hole (H). Also, the reflective layer 262 interposed between the transparent conductive layers 261 and 263 may be exposed on the inner surface of the electrode hole (H). The auxiliary electrode (260) may be covered by a transparent conductive layer (270). The transparent conductive layer (270) can cover the auxiliary electrode (260) patterned with electrode holes (H) and a region of the overcoat layer (160) exposed by the electrode holes (H). At this time, a step is formed in the transparent conductive layer (270) around the electrode hole (H) of the auxiliary electrode (260). Accordingly, grooves 271 covering the electrode holes (H) can be formed in the transparent conductive layer 270 .

The transparent conductive layer (270) may cover the auxiliary electrode (260) as a whole and have a larger area than the auxiliary electrode (260). The transparent conductive layer 270 can increase the overall length of the electrode tip of the auxiliary electrode contact portion CA1. Accordingly, the electrical connection between the auxiliary electrode 260 and the cathode electrode 240 can be stably and easily established at the auxiliary electrode contact portion CA1. In one embodiment, the thickness of the transparent conductive layer (270) may be about 140 Å to 500 Å, but is not so limited.

The transparent conductive layer (270) may be composed of a transparent conductive material such as ITO, IZO or ZnO. For example, the transparent conductive layer (270) may be made of the same material as the transparent conductive layer forming the auxiliary electrode (260). However, the invention is not limited to this.

A bank (250) may be formed to expose a region of the transparent conductive layer (270). For example, the bank (250) may be formed to expose the groove (271) of the transparent conductive layer (270) and cover the remaining area. The exposed area of the transparent conductive layer (270) not covered by the bank (250) can be defined as the auxiliary electrode contact portion (CA1) of the pixel (PX).

In one embodiment, an etching process may be performed on the bank (250) to form an opening corresponding to the auxiliary electrode contact portion (CA1). The etching process may be performed, for example, by applying a selective etchant while applying a mask over the bank (250). After the etching process, the transparent conductive layer 270 can be completely exposed to the outside at the auxiliary electrode contact portion CA1 by removing the mask and the residue of the etchant by an ashing process.

During the ashing process, the transparent conductive layer (270) can protect the inner surfaces of the electrode holes (H). The reflective layer (262) exposed on the inner surface of the electrode hole (H) forms particles due to the ashing process, and may form dark spots on the display panel (50). In this embodiment, since the inner surface of the electrode hole (H) is covered with the transparent conductive layer (270), formation of particles during the ashing process can be prevented.

Since the organic layer (230) and the cathode electrode (240) are widely formed on the substrate (100), they cover a region of the exposed transparent conductive layer (270). At this time, the organic layer (230) having relatively poor step coverage characteristics may be cut off around the groove (271) of the transparent conductive layer (270). In one embodiment, the organic layer (230) may be interrupted at the inner surface of the groove (271), but is not limited to this. By cutting the organic layer (230), a part of the inner surface of the groove (271) of the transparent conductive layer (270) can be exposed without being covered by the organic layer (230).

On the other hand, the cathode electrode (240) with relatively good step coverage characteristics is formed continuously without interruption around the groove (271) of the transparent conductive layer (270). In one embodiment, the cathode electrode (240) may be interrupted around the groove (271) as shown. For example, the cathode electrode (240) may be discontinued at the inner surface of the groove (271). Since the step coverage characteristic of the cathode electrode (240) is better than the step coverage characteristic of the organic layer (230), the cathode electrode (240) is positioned on the inner surface of the groove (271) that is not covered by the organic layer (230). can be contacted directly.

The remnants of the discontinued organic layer (230) and cathode electrode (240) can be stacked in the trench (271). That is, the organic layer (230) and the cathode electrode (240) are disconnected around the groove (271), leaving a residue (230') of the organic layer (230) and a residue (240') of the cathode electrode (240). may be sequentially laminated on the transparent conductive layer (270) within the groove (271).

As described above, the cathode electrode (240) directly contacts the transparent conductive layer (270) at the auxiliary electrode contact portion (CA1). The cathode electrode (240) contacts the connecting electrode (140) through the transparent conductive layer (270) and the auxiliary electrode (260). Since the connection electrode 140 is connected to the second power line PL2 through the auxiliary wiring 110, the cathode electrode 240 can be connected to the second power line PL2.

Also referring to FIG. 3, a sealing layer (300) may be formed over the cathode electrode (240). The encapsulating layer (300) serves to prevent external moisture from penetrating into the light emitting layer (220). The encapsulation layer (300) may be made of an inorganic insulator, or may have a structure in which an inorganic insulator and an organic insulator are alternately laminated, but is not necessarily limited to these.

A cover substrate (400) may be formed on the encapsulation layer (300). The cover substrate (400) may be composed of the same material as the substrate (100). Such a cover substrate (400) can be adhered onto the sealing layer (300) by an adhesive or the like.

In various embodiments, a color filter (410) may be further formed between the encapsulation layer (300) and the cover substrate (400). A color filter (410) may be placed in the emissive area (EA). The color filter (410) is a wavelength-selective filter that selectively transmits only part of the wavelength band of incident light by transmitting light of a specific wavelength band and blocking light of other specific wavelength bands. The optical filter may be composed of a photosensitive resin containing colorants such as pigments or dyes. Light generated by the light emitting device (LD) and passing through the color filter (410) may have any one of red, green, and blue. If the pixel PX displays white, the color filter 410 may be omitted for the corresponding pixel PX.

FIG. 5 is a cross-sectional view showing the auxiliary electrode contact portion (CA2) according to the second embodiment.

As compared with the embodiment of FIG. 4, in the auxiliary electrode contact portion (CA2) according to the second embodiment, the selective etchant used in the etching process of the electrode hole (H) is more concentrated on the reflective layer (265) than on the transparent conductive layer. can have an even greater reactivity to Thereby, the reflective layer (265) may be overetched and an undercut (UC) may occur between the upper and lower transparent conductive layers (261, 263) and the reflective layer (265). That is, the reflective layer (265) is recessed further at the inner surface than the upper and lower transparent conductive layers (261, 263).

In such embodiments, the exposed sides of the reflective layer (265) may have an inverse taper. The groove (273) of the transparent conductive layer (272) covering the auxiliary electrode (264) may have a reverse tapered side surface corresponding to the shape of the auxiliary electrode (264).

Then, the organic layer (230) with poor step coverage characteristics can be more easily broken around the groove (273) of the transparent conductive layer (272). When the inner surface of the groove (273) of the transparent conductive layer (272) is exposed in a larger area due to the discontinuity of the organic layer (230), the cathode electrode (240) formed after the organic layer (230) is exposed to the groove ( 271) can be contacted further positively with the transparent conductive layer (272) on the inner surface.

When the cathode electrode (240) is in direct contact with the transparent conductive layer (272) over a larger area, the electrical resistance between the cathode electrode (240) and the transparent conductive layer (272) is reduced to facilitate power transfer. can be done efficiently.

FIG. 6 is a cross-sectional view showing an auxiliary electrode contact portion (CA3) according to the third embodiment.

Compared with the embodiment of FIG. 5, in the auxiliary electrode contact portion (CA3) according to the third embodiment, the selective etchant used in the etching process of the electrode hole (H) is more likely to penetrate the reflective layer (267) than the transparent conductive layer. can have an even greater reactivity to Thereby, the reflective layer (267) may be overetched and an undercut (UC) may occur between the upper and lower transparent conductive layers (261, 263) and the reflective layer (267). That is, on the inner surface of the electrode hole (H), the reflective layer (267) is recessed further outward than the upper and lower transparent conductive layers (261, 263).

In such embodiments, the exposed sides of the reflective layer (267) may have a tapered shape. The grooves (275) of the transparent conductive layer (274) covering the auxiliary electrodes (266) may have tapered sides corresponding to the shape of the auxiliary electrodes (266).

Then, the cathode electrode (240) with good step coverage characteristics can be more easily formed continuously without being interrupted by the groove (275) of the transparent conductive layer (274). In such an embodiment, the cathode electrode (240) is formed to entirely cover the remainder (230') of the organic layer (230) formed within the groove (275).

When the cathode electrode (240) maintains substantially uninterrupted continuity on the transparent conductive layer (274), the area of direct contact between the cathode electrode (240) and the transparent conductive layer (274) increases, resulting in Contact accuracy can be improved by reducing the electrical resistance between the electrode (240) and the transparent conductive layer (274). Then, the power is efficiently transmitted to the cathode electrode (240), and the power consumption of the display panel (50) can be reduced.

FIG. 7 is a cross-sectional view showing an auxiliary electrode contact portion (CA4) according to the fourth embodiment.

Compared with the first embodiment, in the auxiliary electrode contact part (CA4) according to the fourth embodiment, the auxiliary electrode (268) is formed of a double layer in which the transparent conductive layer (261) and the reflective layer (262) are laminated. may be For example, the auxiliary electrode (268) may consist of a bilayer comprising ITO/Ag.

In such an embodiment, the reflective layer (262) is completely exposed on top of the auxiliary electrode (268). A transparent conductive layer (270) covers all exposed areas of the reflective layer (262). This can prevent particles from being generated from the reflective layer (262).

FIG. 8 is a cross-sectional view showing an auxiliary electrode contact portion (CA5) according to the fifth embodiment.

Compared with the first embodiment, in the auxiliary electrode contact portion (CA5) according to the fifth embodiment, the auxiliary electrode (269) may be formed of a single layer composed of the transparent conductive layer (261). For example, the auxiliary electrode (269) may comprise ITO.

A transparent conductive layer (270) covers the auxiliary electrode (269). The transparent conductive layer (270) may cover the auxiliary electrode (269) as a whole and have a larger area than the auxiliary electrode (269). Such a transparent conductive layer (270) can increase the overall length of the electrode tip of the auxiliary electrode contact portion (CA5). Accordingly, the electrical connection between the auxiliary electrode 269 and the cathode electrode 240 can be stably and easily established at the auxiliary electrode contact portion CA5.

FIG. 9 is a cross-sectional view showing an auxiliary electrode contact portion (CA6) according to the sixth embodiment.

Compared with the first embodiment, the auxiliary electrode contact part (CA6) according to the sixth embodiment omits the auxiliary electrode (260) and includes only the transparent conductive layer (270). Since the auxiliary electrode contact portion (CA6) includes only the transparent conductive layer (270), particles are not generated during the ashing process of the bank (250). Also, the transparent conductive layer 270 is formed relatively wide on the auxiliary electrode contact portion CA6, so that the length of the electrode tip of the auxiliary electrode contact portion CA6 can be increased.

10 to 16 are diagrams illustrating a method of manufacturing a display device according to one embodiment. In FIGS. 10 to 16, illustration of the lower layer of the overcoat layer 160 is omitted for convenience of explanation. However, circuit elements, auxiliary wirings 110 and connection electrodes 140 may be formed under the overcoat layer 160 as described with reference to FIG.

Referring to Figures 10 and 11, an auxiliary electrode (260) is formed on the overcoat layer (160) in the auxiliary electrode contact area (CA). Although not shown, the auxiliary electrode (260) is connected to the connection electrode (140).

The auxiliary electrode (260) may be formed of a triple layer consisting of a transparent conductive layer (261)/reflective layer (262)/transparent conductive layer (263). The transparent conductive layers (261, 263) may for example consist of ITO and the reflective layer (262) may consist of a metallic material such as silver or a silver alloy. At least one electrode hole (H) is formed in the auxiliary electrode (260). The transparent conductive layer (261)/reflective layer (262)/transparent conductive layer (263) constituting the auxiliary electrode (260) may be exposed on the inner surface of the electrode hole (H).

As shown in FIG. 10, the auxiliary electrode 260 is formed by sequentially stacking a transparent conductive layer 261/reflective layer 262/transparent conductive layer 263, and then, as shown in FIG. It may be formed by batch etching (for example, wet etching) of the triple layer while applying a mask containing a pattern corresponding to the electrode holes (H).

Referring to FIG. 12, a transparent conductive layer (270) may then be formed on the auxiliary electrode (260). A transparent conductive layer (270) is formed to cover the auxiliary electrode (260) patterned with electrode holes (H) and a region of the overcoat layer (160) exposed by the electrode holes (H). good too. At this time, a step is formed in the transparent conductive layer (270) around the electrode hole (H) of the auxiliary electrode (260). Thereby, grooves 271 covering the electrode holes (H) may be formed in the transparent conductive layer 270 .

The transparent conductive layer (270) may cover the auxiliary electrode (260) as a whole and have a larger area than the auxiliary electrode (260). The length of the entire electrode tip of the auxiliary electrode contact part (CA) can be increased through the transparent conductive layer (270). Accordingly, the electrical connection between the auxiliary electrode 260 and the cathode electrode 240 can be stably and easily established at the auxiliary electrode contact portion (CA). In one embodiment, the thickness of the transparent conductive layer (270) may be about 140 Å to 500 Å, but is not so limited.

The transparent conductive layer (270) may be composed of a transparent conductive material such as ITO, IZO or ZnO. For example, the transparent conductive layer (270) may be made of the same material as the transparent conductive layer forming the auxiliary electrode (260). However, the invention is not limited to this.

Referring to FIG. 13, banks (250) may then be formed on the transparent conductive layer (270). The bank (250) may be formed to expose a portion of the transparent conductive layer (270), for example, the periphery of the groove (271), but cover the rest of the area.

In one embodiment, the bank (250) may have a structure in which a hydrophilic bank (251) and a hydrophobic bank (252) are stacked. The hydrophilic bank 251 is made of a hydrophilic inorganic insulating material, such as silicon oxide (SiO2) or silicon nitride (SiNx), to allow the solution to spread well during the formation of the light emitting layer 220, which will be described later. .

A hydrophobic bank (252) may be formed in a partial area on the hydrophilic bank (251). Hydrophobic banks (252) may be formed so that at least a portion of the surface is hydrophobic. For example, the hydrophobic bank 252 may be formed by a photolithography process after applying a solution in which a hydrophobic material such as fluorine (F) is mixed with an organic insulator. Hydrophobic substances such as fluorine can migrate to the top of the hydrophobic bank (252) by the light irradiated in the photolithography process, so that the top surface of the hydrophobic bank (252) has hydrophobic properties, The remaining portion can have hydrophilic properties.

In such an embodiment, after the hydrophilic banks (251) are formed on the transparent conductive layer (270), the hydrophobic banks (252) may be formed on the hydrophilic banks (251). Specifically, the hydrophilic bank (251) is formed by laminating a hydrophilic inorganic insulating layer on the transparent conductive layer (270), and applying a mask corresponding to the shape of the hydrophilic bank (251). It may be formed by etching the insulating layer. After the etching process, the electrode hole (H) of the sub-electrode (260) stacked thereunder and its peripheral region may be exposed on the top.

After the hydrophilic bank (251) etching step, an ashing step may be performed to remove the mask and residue. During the ashing process, the transparent conductive layer (270) can protect the inner surfaces of the electrode holes (H). Since the inner surface of the electrode hole (H) is covered with the transparent conductive layer (270), formation of particles during the ashing process can be prevented.

After that, a solution in which a hydrophobic substance such as fluorine (F) is mixed with an organic insulator is coated on the hydrophilic bank 251, and then a hydrophobic bank 252 is formed by a photolithography process. good.

Referring to Figure 14, an organic layer (230) is formed. The organic layer (230) can be formed in a large area by an evaporative deposition method such as thermal evaporation or a physical vapor deposition method such as sputtering to cover the bank (250) and the transparent conductive layer (270). can. In one embodiment, the organic layer (230) may be interrupted around the trench (271) of the transparent conductive layer (270) due to step coverage properties. By cutting the organic layer (230), a part of the inner surface of the groove (271) of the transparent conductive layer (270) can be exposed without being covered by the organic layer (230). A remnant (230') of the discontinued organic layer (230) may be deposited in the trench (271).

Referring to FIG. 15, a cathode electrode (240) is formed on the organic layer (230). The cathode electrode 240 may be formed over a large area by an evaporative deposition method such as thermal deposition or a physical vapor deposition method such as sputtering to cover the organic layer 230 . The cathode electrode (240) may be interrupted on the inner surface of the groove (271) due to step coverage characteristics. Since the step coverage characteristic of the cathode electrode (240) is better than the step coverage characteristic of the organic layer (230), the cathode electrode (240) is positioned on the inner surface of the groove (271) that is not covered by the organic layer (230). can be contacted directly. A remnant (240') of the severed cathode electrode (240) may be deposited in the groove (271).

Referring to FIG. 16, a sealing layer (300) may be formed over the cathode electrode (240). Depending on the embodiment, various functional layers such as a protective layer, a polarizing layer and a touch screen layer may be further laminated on the encapsulation layer (300).

Those skilled in the art to which the present invention pertains will appreciate that the present invention can be embodied in other specific forms without changing its technical spirit or essential features. deaf. Accordingly, the above-described embodiments are to be understood in all respects as illustrative and not restrictive. The scope of the present invention is indicated by the claims below rather than the detailed description above, and all changes or modifications derived from the meaning and scope of the claims and their equivalent concepts are within the scope of the present invention. should be construed as included.

1: Display Device 10: Timing Control Section 20: Gate Driving Section 30: Data Driving Section 40: Power Supply Section 50: Display Panel

Claims (17)

a substrate including a light emitting region and an auxiliary electrode contact portion;
an auxiliary electrode disposed in the auxiliary electrode contact portion and having an electrode hole;
a transparent conductive layer covering the auxiliary electrode and having grooves formed above the electrode holes;
a first bank exposing the periphery of the groove of the transparent conductive layer and covering the remaining area;
a second bank formed on the first bank;
an organic layer formed on the second bank and the exposed transparent conductive layer; and a cathode electrode formed on the organic layer,
The cathode electrode is
A display device in direct contact with the inner surface of the groove. the organic layer is cut off around the groove to expose the inner surface of the groove;
2. The display device of claim 1, wherein the cathode electrode directly contacts the exposed inner side surface of the groove. 2. The display device of claim 1, wherein the transparent conductive layer entirely covers the auxiliary electrodes and has a larger area than the auxiliary electrodes. The auxiliary electrode has a structure in which a first transparent conductive layer, a reflective layer and a second transparent conductive layer are laminated,
2. The display device of claim 1, wherein the reflective layer is exposed on inner surfaces of the electrode holes and covered by the transparent conductive layer. 5. The display device of claim 4, wherein the reflective layer is recessed further from the inner surface of the electrode hole than the first and second conductive layers. The reflective layer has a reverse tapered side surface,
6. The display device according to claim 5, wherein the groove of the transparent conductive layer has a reverse tapered shape corresponding to the shape of the reflective layer. The reflective layer is tapered on the side,
6. The display device according to claim 5, wherein the groove portion of the transparent conductive layer is tapered corresponding to the shape of the reflective layer. 2. The display device of claim 1, wherein the auxiliary electrode has a laminated structure of a first transparent conductive layer and a reflective layer, and the exposed reflective layer is entirely covered by the transparent conductive layer. 2. The display device according to claim 1, wherein the auxiliary electrode has a structure in which a first transparent conductive layer and a reflective layer are laminated, and the first transparent conductive layer is entirely covered by the transparent conductive layer. 2. The display device according to claim 1, wherein said auxiliary electrode has a structure in which a first transparent conductive layer is laminated, and said first transparent conductive layer is entirely covered by said transparent conductive layer. the first bank is a hydrophilic bank,
2. The display device of claim 1, wherein said second bank is a hydrophobic bank. forming an auxiliary electrode on the auxiliary electrode contact portion of the substrate including the light emitting region and the auxiliary electrode contact portion;
forming a transparent conductive layer covering the auxiliary electrode;
exposing at least one area of the transparent conductive layer and forming a bank covering the remaining area;
A method of manufacturing a display device, comprising: forming an organic layer on the bank and the exposed transparent conductive layer; and forming a cathode electrode on the organic layer. 13. The method of manufacturing a display device according to claim 12, wherein the transparent conductive layer is formed to cover the auxiliary electrode as a whole and have a larger area than the auxiliary electrode. The step of forming the auxiliary electrode includes:
laminating a first transparent conductive layer, a reflective layer and a second transparent conductive layer; and performing an etching process while applying a mask to form an electrode hole;
13. The method of manufacturing a display device according to claim 12, wherein the reflective layer is exposed on inner surfaces of the electrode holes and covered with the transparent conductive layer. 15. The method of claim 14, wherein the reflective layer is over-etched from the first and second transparent conductive layers during the etching step. The step of forming the bank includes:
forming an insulating layer;
15. The method of manufacturing a display device according to claim 14, comprising the steps of: performing an etching process with a mask applied to form the bank; and performing an ashing process to remove the mask. The organic layer and the cathode electrode are
17. The method of manufacturing a display device according to claim 16, wherein the display device is formed to have a large area on the substrate by an evaporation deposition method or a physical vapor deposition method.

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